1. Field of the Invention
This invention relates to a needle bearing assembling apparatus.
2. Description of the Related Art
A hitherto known needle bearing assembling apparatus is formed so that, when a needle bearing is assembled, needles are fed one by one to a rotating index shaft so as to annularly arrange a predetermined number of needles and thereby insert the needles into a hollow on an inner side of a roller outer race. Such a needle bearing assembling apparatus has already been known from Japanese Patent Laid-Open No. 50341/1993.
In the above-described known needle bearing assembling apparatus, needles are fed one by one onto an inner side of a roller outer race, so that it takes much time to insert a predetermined number of needles thereinto in an annular configuration. Therefore, it is difficult to say that this needle bearing assembling apparatus has a high operation efficiency. Moreover, feeding a predetermined number of needles one by one makes it difficult to ascertain a number thereof fed in practice, and causes an incidence of shortage of a number of the needles to increase and a yield of a needle bearing to lower.
The present invention has been made in view of the above-described circumstances, and provides a needle bearing assembling apparatus capable of solving problems encountered in the known needle bearing assembling apparatus, and having a high operation efficiency and a high yield.
The inventors of the present invention earnestly studied attainment of such a needle bearing assembling apparatus to discover that a needle bearing assembling apparatus provided with a thrust unit adapted to feed needles sequentially in a row, an arrangement unit adapted to properly arrange needles fittable within a hollow formed on an inner side of a roller outer race, and a mechanism having a device for fitting the arranged needles firmly into the hollow on the inner side of the roller outer race, caused an operation efficiency of the above-mentioned known needle bearing assembling apparatus to be improved. The inventors have also discovered that feeding the needles collectively facilitates ascertaining of a number of passing needles, and that providing a needle regulating unit adapted to arrange needles annularly so that the needles extend in a predetermined direction enables an occurrence of a fall of needles during collective feeding thereof to be prevented, and a needle bearing to be assembled at a high yield.
The inventors further discussed a various points repeatedly to come to complete the present invention.
According to a first aspect of the present invention, the needle bearing assembling apparatus has a thrust unit adapted to sequentially feed rows of needles, an arrangement unit adapted to properly arrange needles, fed by the thrust unit, into a configuration that corresponds to a configuration of a hollow formed on an inner side of a roller outer race, and an insertion device adapted to fit the arranged needles firmly in the hollow on the inner side of the roller outer race.
According to a second aspect of the present invention, the needle bearing assembling apparatus is in accordance with the first aspect, wherein the needle arrangement unit includes an annularly formed arrangement jig adapted to arrange a predetermined number of needles, fed in a row, into the configuration such that the needles can be fitted into the hollow formed on the inner side of the roller outer race.
According to a third aspect of the present invention, the needle bearing assembling apparatus is in accordance with the first or second aspects, wherein the arrangement unit has a mechanism adapted to be moved vertically until the mechanism gets a predetermined portion of the roller outer race so as to fit the needles firmly into the hollow on the inner side of the roller outer race.
According to a fourth aspect of the present invention, the needle bearing assembling apparatus is in accordance with any one of the first to third aspects, wherein a part feeder is provided for sequentially supplying rows of needles to a storage unit, which storage unit has, a multistage storage mechanism adapted to arrange the rows of needles in multiple stages, the thrust unit includes a needle pusher for sequentially feeding the rows of needles from the storage unit into the arrangement unit until the needles are arranged annularly, and a needle regulating unit is provided for controlling a direction in which the needles are fed into the arrangement unit so that the needles extend in a predetermined direction.
According to a fifth aspect of the present invention, the needle bearing assembling apparatus is in accordance with any one of the first to fourth aspects, wherein provided is a member for supplying grease onto outer circumferential surfaces of the needles while the needles are in the configuration.
According to a sixth aspect of the present invention, the needle bearing assembling apparatus is in accordance with the first aspect, wherein the hollow formed on the inner side of the roller outer race is defined between an inner circumferential surface of the roller outer race and an outer circumferential surface of a roller inner race which is combined and fed with the roller outer race.